[Python][Cook][265-266] 實作class 的 __str__, __repr__ 的效果

目的: 觀察實作__str__, __repr__的效果

實作前:

#!/usr/bin/python



class A:

        def __init__(self, x, y):

                self.x = x

                self.y = y



a = A(5, 6)

print a

print "%r" % a

print "{0!r}".format(a)

print str(a)

<__main__ data-blogger-escaped-.a="" data-blogger-escaped-0x7f433e42db48="" data-blogger-escaped-at="" data-blogger-escaped-instance="">
<__main__ data-blogger-escaped-.a="" data-blogger-escaped-0x7f433e42db48="" data-blogger-escaped-at="" data-blogger-escaped-instance="">
<__main__ data-blogger-escaped-.a="" data-blogger-escaped-0x7f433e42db48="" data-blogger-escaped-at="" data-blogger-escaped-instance="">
<__main__ data-blogger-escaped-.a="" data-blogger-escaped-0x7f433e42db48="" data-blogger-escaped-at="" data-blogger-escaped-instance="">

實作後:

#!/usr/bin/python



class A:

        def __init__(self, x, y):

                self.x = x

                self.y = y

        def __str__(self):

                return 'This is A __str__'

        def __repr__(self):

                return '<A __repr__>'



a = A(5, 6)

print a

print "%r" % a

print "{0!r}".format(a)

print "{0!s}".format(a)

print str(a)

This is A __str__
<A __repr__>
<A __repr__>
This is A __str__
This is A __str__